（抱歉我的英文不好，我是意大利人） 我是Android编程的新手，我遇到了这个问题： 我每隔“1”秒需要加速度计数据（sqrt（x * x ..）的最大值和最小值）并且如果它们的差值的绝对值（Δ）是<1秒。 0.4 * Gravity_earth，我需要在条件的前5秒内获得的数据，然后我计算最大值。如果值> THRESHOLD我标志着“不堕落”或“堕落”。 有人能解决这个我的问题吗？ 谢谢！ 这是我的解决方案：
public class MainActivity extends Activity implements SensorEventListener{
SensorManager sm;
float acc;
private float [] sensorData;
float azimuth,pitch,roll;
float omegaMagnitude;
//ArrayList
ArrayList<Float> tutteLeAcc =new ArrayList();
ArrayList<Float> previousAcc=new ArrayList();
Iterator<Float> it;
Iterator<Float> it1;
float accMax;
float accMin;
float accPreviousMax;
float deltaAcc;
private static final String TAG = "SIMTHR";
public static final int MSG_C = 3;
public static final int MSG_D = 4;
WorkerThread mWorkerThread;
WorkerThread1 mWorkerThread1;
boolean isRunning = false;
boolean running;
Button btnStart,btnStop;
TextView txtLog;
int tt = 0;
boolean caduta;
final Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_C:
//it=tutteLeAcc.iterator();
txtLog.setText("");
txtLog.append("\nAmax: "+Float.toString(accMax)+" Amin: "+Float.toString(accMin)+" dA: "+Float.toString(deltaAcc));
tutteLeAcc.clear();
break;
case MSG_D:
txtLog.append("\nPreviousACCmax: "+Float.toString(accPreviousMax)+"\n");
//previousAcc.clear();
break;
}
caduta=Detection(previousAcc,deltaAcc);
//previousAcc.clear();
}
};
class WorkerThread extends Thread {
public Handler mCallerHandler;
private int nn = 1;
public WorkerThread(Handler handler) {
mCallerHandler = handler;
Log.i(TAG,"create WorkerThread");
}
public void run() {
nn = 0;
while(running){
try {
Log.i(TAG,"WorkerThread inizia qua");
if (mCallerHandler!=null) {
accMax=trovaMax(tutteLeAcc);
accMin=trovaMin(tutteLeAcc);
deltaAcc=Math.abs(accMax-accMin);
Thread.sleep(1000);
mCallerHandler.obtainMessage(MSG_C).sendToTarget();
Log.i(TAG,"WorkerThread finisce qua");
}
} catch (InterruptedException e) {
Log.e(TAG,"errore in WorkerThread "+e.toString());
}
}
}
public synchronized void start() {
running=true;
super.start();
Log.i(TAG,"WorkerThread avviato");
}
public synchronized void cancel() {
running=false;
Log.i(TAG,"WorkerThread avviato");
}
}
class WorkerThread1 extends Thread {
public Handler mCallerHandler;
private int nn = 1;
public WorkerThread1(Handler handler) {
// salvo l'handler dei messaggi dell'activity chiamante
mCallerHandler = handler;
Log.i(TAG,"create WorkerThread1");
}
public void run() {
nn = 0;
while(running){
try {
Log.i(TAG,"WorkerThread1 inizia qua");
if (mCallerHandler!=null) {
accPreviousMax=trovaMax(previousAcc);
Thread.sleep(5000);
mCallerHandler.obtainMessage(MSG_D).sendToTarget();
Log.i(TAG,"WorkerThread finisce qua");
}
} catch (InterruptedException e) {
Log.e(TAG,"errore in WorkerThread "+e.toString());
}
}
}
// avvio del thread
public synchronized void start() {
running=true;
super.start();
Log.i(TAG,"WorkerThread avviato");
}
public synchronized void cancel() {
running=false;
Log.i(TAG,"WorkerThread avviato");
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Log.i(TAG,"Activity ONCREATE");
sm = (SensorManager)getSystemService(SENSOR_SERVICE);
sm.registerListener(this,sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),SensorManager.SENSOR_DELAY_NORMAL);
sm.registerListener(this, sm.getDefaultSensor(Sensor.TYPE_ORIENTATION), SensorManager.SENSOR_DELAY_NORMAL);
sm.registerListener(this, sm.getDefaultSensor(Sensor.TYPE_GYROSCOPE), SensorManager.SENSOR_DELAY_NORMAL);
// oggetti della User Interface
btnStart = (Button) findViewById(R.id.btnStart);
btnStop=(Button)findViewById(R.id.btnStop);
txtLog = (TextView) findViewById(R.id.txtLog);
txtLog.setTextColor(Color.WHITE);
sensorData = new float[9];
// button per l'avvio del thread
btnStart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mWorkerThread!=null&&mWorkerThread1!=null) {
mWorkerThread.cancel();
mWorkerThread1.cancel();
mWorkerThread = null; mWorkerThread1 = null;
txtLog.append("\nrichiesto arresto THREAD 1 e 2 #"+Integer.toString(tt)+"\n");
}
tt++;
mWorkerThread = new WorkerThread(mHandler);
mWorkerThread1 = new WorkerThread1(mHandler);
mWorkerThread.start(); mWorkerThread1.start();
isRunning = true;
txtLog.append("\nrichiesto avvio THREAD 1 e 2\n");
}
});
// button per l'arresto del thread
btnStop.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mWorkerThread!=null&&mWorkerThread1!=null) {
mWorkerThread.cancel();
mWorkerThread1.cancel();
mWorkerThread = null; mWorkerThread1 = null;
txtLog.append("\nrichiesto arresto THREAD 1 e 2\n");
}
isRunning = false;
}
});
}
public void Deregistra(){
sm.unregisterListener(this);
}
public void Registra(){
sm.registerListener(this,sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),SensorManager.SENSOR_DELAY_NORMAL);
}
@Override
public void onSensorChanged(SensorEvent event) {
float [] values = event.values;
synchronized (this) {
if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
sensorData[0] = event.values[0];
sensorData[1] = event.values[1];
sensorData[2] = event.values[2];
if ((sensorData[3] != 0)||(sensorData[4] != 0)||(sensorData[5] != 0)
||(sensorData[6] != 0)||(sensorData[7] != 0)||(sensorData[8] != 0))
{
float ax=sensorData[0];
float ay=sensorData[1];
float az=sensorData[2];
acc=(float) Math.sqrt((ax*ax)+(ay*ay)+(az*az));
/*
tutteLeAcc.add(acc);
accMax=trovaMax(tutteLeAcc);
accMin=trovaMin(tutteLeAcc);
deltaAcc=Math.abs(accMax-accMin);
*/
tutteLeAcc.add(acc);
previousAcc.add(acc);
}
}
else if (event.sensor.getType() == Sensor.TYPE_ORIENTATION ) {
sensorData [3] = values[0];
sensorData [4] = values[1];
sensorData [5] = values[2];
if ((sensorData[0] != 0)||(sensorData[1] != 0)||(sensorData[2] != 0)
||(sensorData[6] != 0)||(sensorData[7] != 0)||(sensorData[8] != 0))
{
azimuth=sensorData[3];
pitch=sensorData[4];
roll=sensorData[5];
}
}
else if(event.sensor.getType()==Sensor.TYPE_GYROSCOPE){
sensorData [6] = values[0];
sensorData [7] = values[1];
sensorData [8] = values[2];
final float gx=sensorData[6];
final float gy=sensorData[7];
final float gz=sensorData[8];
if ((sensorData[0] != 0)||(sensorData[1] != 0)||(sensorData[2] != 0)
||(sensorData[3] != 0)||(sensorData[4] != 0)||(sensorData[5] != 0))
{
float axisX = sensorData[6];
float axisY = sensorData[7];
float axisZ = sensorData[8];
// Calculate the angular speed of the sample
omegaMagnitude = (float) Math.sqrt((axisX*axisX) + (axisY*axisY) + (axisZ*axisZ));
}
}
}
}
public float trovaMin(ArrayList<Float> a){
Iterator<Float> it=a.iterator();
float min=a.get(0);
while(it.hasNext()){
Float x=it.next();
if(x<min){
min=x;}
}
return min;
}
public float trovaMax(ArrayList<Float> a){
Iterator<Float> it=a.iterator();
float max=a.get(0);
while(it.hasNext()){
Float x=it.next();
if(x>max){
max=x;}
}
return max;
}
public boolean Detection(ArrayList<Float> accPrec,float delta){
boolean intentional=true, static=true, lying=false;
float am;
if(delta<0.4*SensorManager.GRAVITY_EARTH){
statico=true;
Log.v("STATIC?", "yes");
if(static){
if(Math.abs(pitch)>=140||Math.abs(pitch)<30){
lying=true;
Log.v("LYING?", "yes");
if(allungato){
am=findMax(accPrec);
if(am>2.5*SensorManager.GRAVITY_EARTH||omegaMagnitude>200){
intentional=true;
Log.v("INTENTIONAL?", "yes");
}else{
intenzionale=false;
Log.v("INTENTIONAL?", "no");
}
}
}else {
lying=false;
Log.v("STANDING?", "yes");
}
}
} else {
static=false;
Log.v("STATIC?", "no");
}
if(static&&lying&&!intenional)
return true;
else return false;
}
}
答案 0 :(得分：0)
没有确切的方法可以确定哪一个样品得到了哪一个。但您可以通过固定加速度计更新的频率来估算它。
假设我们要求第二个（50赫兹）50个样本
这个
sm.registerListener(this,sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),50000000);
不要使用Android传感器延迟常量（即SensorManager.SENSOR_DELAY_NORMAL），它们对于不同的供应商设备是不同的。
现在只需运行一个简单的计数器0到50（没有其他方式:(）
我希望这会对你有所帮助。
答案 1 :(得分：0)
我的建议是以最大可能的频率运行传感器： sm.registerListener（此，sm.getDefaultSensor（Sensor.TYPE_ACCELEROMETER），SensorManager.SENSOR_DELAY_FASTEST）; 因为，无论如何，在任何情况下，设备都没有严格遵守用数字表示的费率;另外，自API v.2.3起支持“数字”速率。 然后，您应该像这样编写onSensorChanged方法。 注释：检查当前时间是否超过latestSensorChange + DELTASENSOR（即您要在传感器值之间等待的毫秒数）。
@Override
public void onSensorChanged(SensorEvent event) {
float[] values = event.values;
long Now = System.currentTimeMillis();
if (Now > (latestSensorChange + DELTASENSOR)) {
/* if ((mDbHelper.getOldVal(BreathDbAdapter.IDX_X) != values[BreathDbAdapter.IDX_X]) ||
(mDbHelper.getOldVal(BreathDbAdapter.IDX_Y)!= values[BreathDbAdapter.IDX_Y]) ||
(mDbHelper.getOldVal(BreathDbAdapter.IDX_Z)!= values[BreathDbAdapter.IDX_Z])) {
*/
msg = "Accelerometer: " + values[0]
+ ", " + values[1] + ", " + values[2] + " at " + Now + " (EndTime =" + EndTime +")";
mTextViewAccelerometer.setText(msg);
Log.v(TAG, msg );
latestSensorChange = Now;
if (Now > EndTime) {
Log.v(TAG,"Fine del Test at " + Now);
finish();
}
}
请让我知道它是否有帮助（sennòtivengocercareperchèsonoItaliano anch'io :-)） Checco